org.simpleframework.xml.core.Instantiator Maven / Gradle / Ivy
/*
* Instantiator.java July 2006
*
* Copyright (C) 2006, Niall Gallagher
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
package org.simpleframework.xml.core;
import java.lang.reflect.Constructor;
import org.simpleframework.xml.strategy.Value;
/**
* The Instantiator is used to instantiate types that
* will leverage a constructor cache to quickly create the objects.
* This is used by the various object factories to return type
* instances that can be used by converters to create the objects
* that will later be deserialized.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.core.Instance
*/
class Instantiator {
/**
* This is used to cache the constructors for the given types.
*/
private final ConstructorCache cache;
/**
* Constructor for the Instantiator object. This will
* create a constructor cache that can be used to cache all of
* the constructors instantiated for the required types.
*/
public Instantiator() {
this.cache = new ConstructorCache();
}
/**
* This will create an Instance that can be used
* to instantiate objects of the specified class. This leverages
* an internal constructor cache to ensure creation is quicker.
*
* @param value this contains information on the object instance
*
* @return this will return an object for instantiating objects
*/
public Instance getInstance(Value value) {
return new ValueInstance(this, value);
}
/**
* This will create an Instance that can be used
* to instantiate objects of the specified class. This leverages
* an internal constructor cache to ensure creation is quicker.
*
* @param type this is the type that is to be instantiated
*
* @return this will return an object for instantiating objects
*/
public Instance getInstance(Class type) {
return new ClassInstance(this, type);
}
/**
* This method will instantiate an object of the provided type. If
* the object or constructor does not have public access then this
* will ensure the constructor is accessible and can be used.
*
* @param type this is used to ensure the object is accessible
*
* @return this returns an instance of the specific class type
*/
public Object getObject(Class type) throws Exception {
Constructor method = cache.get(type);
if(method == null) {
method = type.getDeclaredConstructor();
if(!method.isAccessible()) {
method.setAccessible(true);
}
cache.put(type, method);
}
return method.newInstance();
}
}